1. Field of the Invention
The present invention relates to a device for guiding recording papers, which works to restrict moving directions of the recording papers in the copying machines and in the printing machines.
2. Description of the Prior Art
In supplying recording papers onto the periphery of a photosensitive drum on which the toner image has been formed in an electrophotographic reproducing machine, any clearance between the peripheral surface of the photosensitive drum and the recording paper makes it difficult to correctly transfer the toner image onto the recording paper as has been widely known. Therefore, strict precision is required for the clearance between the photosensitive drum and the tip of a guide plate which supplies the recording papers onto the peripheral surface of the photosensitive drum. According to the conventional devices, therefore, the guide plate is adjustably mounted on the fixed portion of the apparatus by such position-adjusting means as elongated holes or the like, and the distance between the tip of the guide plate and the peripheral surface of the photosensitive drum is determined by using a gauge in the assembling steps. With such a guide device, however, the adjusting operation must be carried out for the individual machines. Further, the adjusting operation which is carried out in narrow space impairs the operation efficiency and reduces the mass-production efficiency.
To eliminate the above-mentioned defects, a method has been proposed in Japanese Patent Laid-Open No. 135,875/1980 that was laid open to public inspection. According to this method, provision is made of a rotary portion that comes into contact with both ends of the photosensitive drum where no image is formed, and a guide shaft which is formed together with the rotary portion as a unitary structure maintaining a predetermined clearance relative to the surface of the photosensitive drum, thereby to guide the transfer papers. This method is capable of defining a clearance that is effective for enhancing the transfer effects. However, since end portion of the guide shaft comes into contact with the surface of the photosensitive drum to rotate, the shaft is subject to be worn out when the copying operation is carried out at high speeds, or the toner infiltrates into the bearings and the shaft fails to rotate smoothly. Consequently, part of the rotary portion is rubbed by the surface of the photosensitive drum and is worn out.